Alesis ACTIVE M1 Quick Start Owner's Manual page 12

Speaker Placement
The placement of your speakers has a huge impact on how well they will perform
in your studio.
Although nearfield studio monitors (such as these M1Active 520/620s) are
designed to be more forgiving when it comes to placement, you should do your
best to make sure they form an equilateral triangle relative to your head. In other
words, make sure that each speaker is equally distant from both your head as well
as the other speaker. Once each speaker has been placed, rotate the speakers
slightly so that the drivers are pointing toward the engineer.
Take a look at the diagram below. Notice that the distance from the engineer's
head to each speaker is the same as the distance between the left and right
speakers. Also note that the speakers are turned slightly so that the drivers are
facing the engineer.
This is an ideal setup but if it is not practical (or possible) to do this, try to match
this setup as closely as possible.
The speakers and
listener should be at
the three corners of
a triangle having
equal length sides
10
Prime Listening Position